Outboard motor lock guide: how to secure your outboard and battery
An outboard is one of the easiest things on a boat to steal — and one of the most expensive to replace. This guide explains how outboard motor locks work, what to look for, and how to secure an ePropulsion Spirit, where the removable battery is the weak point.
Why outboards get taken
Outboards are valuable, popular, and held on with a handful of bolts, so removing one takes minutes and needs no special tools. Dinghies, tenders, and small boats left on moorings, drives, and marina pontoons are the usual targets. A visible lock does not make theft impossible — it makes your outboard the slow, awkward option, which is usually enough.
The four main types of outboard motor lock
Most outboard security falls into four groups. Many owners use a combination — a lock for the engine, and a lock for anything removable like the battery.
Clamp lock
A bar or collar that locks across the outboard's clamp bracket and transom bolts, so the engine cannot be unbolted or lifted off the boat. The most common way to lock an outboard motor to the boat itself.
Battery lock
For electric outboards with a removable battery, this is where most thefts happen: the battery lifts out and can be carried away in seconds. A battery lock blocks the battery handle so it cannot be lifted out of the motor.
Propeller lock
A cone or collar fitted over the propeller nut. It stops the propeller being taken, but on most motors it does not stop the whole engine being removed.
Tilt and tilt-tube locks
Small padlocks or pins that lock the engine in the tilted position. Useful on tenders stored afloat, but they protect the engine's position rather than stop removal.
How to lock an outboard motor
- 1Lock the motor to the boat. A stainless-steel transom lock across the clamp bracket and transom bolts stops the engine being unbolted and lifted off — these are available from most online chandleries.
- 2Lock the removable battery. If your outboard has a removable battery — as every ePropulsion Spirit does — fit a battery lock that blocks the battery handle so it cannot be lifted out.
- 3Remove or secure the rest of the kit. Take chargers, spare keys, and small valuables off the boat, or lock them in a locker.
- 4Think about where the boat is kept. A lock buys time and deters opportunists; parking somewhere overlooked and covered adds a second layer.
The weak point on an ePropulsion Spirit
The removable battery
Every ePropulsion Spirit runs on a removable battery that lifts out of the top of the motor. That is brilliant for charging at home — and it is exactly what a thief wants, because the most valuable part of the outboard can be lifted out and carried away in seconds, even with the motor still bolted to the boat.
How the ePropLock Battery Lock works
The ePropLock Battery Lock fits over the battery on the top of the motor and blocks the battery handle, so the battery cannot be lifted out of the outboard. It is machined and assembled in Devon from glass-fibre reinforced polymer composite for strength, excellent outdoor weathering and UV resistance, with 316 marine-grade stainless steel custom parts and other corrosion-resistant components for life on the water.
Want to secure the motor itself as well? We would recommend a stainless steel transom lock, available from most online chandleries.
What to look for when choosing a lock
- Marine-grade stainless steel hardware, such as 316, for parts that live in the salt air
- UV-stable, weather-resistant bodies — glass-fibre reinforced polymer composites are made for outdoor use
- A spare set of keys, or two sets supplied as standard
- A guarantee you can actually use — ideally a lifetime one
- A design that fits your specific outboard, not a one-size-fits-all clamp
Will it fit my Spirit?
The ePropLock Battery Lock works across the ePropulsion Spirit range.
We are currently testing an option for the new Spirit 2 generation — it will be available soon. ePropLock is an aftermarket security product made by ePropulsion owners, and is not manufactured or endorsed by ePropulsion.
Frequently asked questions
How do I lock an ePropulsion Spirit outboard?
The ePropLock Battery Lock fits over the battery on the top of the motor and blocks the battery handle, so the removable battery cannot be lifted out of the outboard. That is the part most thieves are after, because the battery can be carried away in seconds even with the motor still bolted to the boat.
How do I secure the ePropulsion outboard itself?
We would recommend using a stainless steel transom lock, available from most online chandleries.
Do outboard motor locks actually stop theft?
No lock makes a boat theft-proof, but a visible, well-made lock makes stealing your outboard slow, noisy, and awkward — which is usually enough to send a thief to an easier target.
Which Spirit models does the ePropLock fit?
The Battery Lock is compatible with ePropulsion Spirit Battery Plus, Spirit 1.0 Plus, and Spirit Evo. We are currently testing an option for the new Spirit 2 generation, and it will be available soon.
How much does an outboard motor lock cost in the UK?
The ePropLock Battery Lock is £49.99 with our Low Season Discount (was £65 — save £15.01) and comes with 2 sets of keys, and delivery is free within the UK.
Secure your ePropulsion Spirit for £49.99
The ePropLock Battery Lock is £49.99 with our Low Season Discount (was £65 — save £15.01) and comes with 2 sets of keys. Free postage to UK addresses, worldwide delivery charged at checkout, and every ePropLock is backed by our Lifetime Guarantee.